Will a xr200 6 speed tranny fit in stock 200x cases?

[Shorty]

I'm not 100% shure. I would also like to know if I need the whole bottom end or just the tranny,shifter forks, ETC ETC. And I can't remember the years that you can use the 6 speed tranny out of.

I think its 1983-85???

[TheRealFatShady]

I have a spare bottom end from one, I believe 00? (86-2002 should work as well) I was going to use the cylinder/piston/valves/cam from a 200s on the XR bottom end, maybe I would buy an XR or X cam, and 200x kick start gears to kick forward.

[Dirtcrasher]

Yes, but some stuff has to be done. Shortline would probably know best but JennDn or something (mostly on .ORG) has done the swap and knows the dealio........

[greenhuman]

You can use the XR gears, selectors and forks in your standard cases or use the XR cases as they are the same as the '83 - '85 200X cases.
I found the six speed useful for a high revving engine but with a stroker stick with the five speed.

[Shorty]

You can use the XR gears, selectors and forks in your standard cases or use the XR cases as they are the same as the '83 - '85 200X cases.
I found the six speed useful for a high revving engine but with a stroker stick with the five speed.

So witch one should I use on a 252cc big bore/ stroker atc 200x motor? This motor is gonna have at least 14,500 RPM. Also I heard when really you mod a 200x motor 2nd and 3rd gears tend to shatter.

[greenhuman]

The six speed is a lot weaker as there are 6 thinner gears in the same space as the 5 thicker gears. I would still stay with the five speed because with a big engine you won't be needing to go thru the gears all the time to keep it going. I have never heard of this 2nd and 3rd gear weakness.
I have built some nasty 200X engines and never had a gearbox problem.
Don't forget to undercut the kick starter gears for reliability.

[WIkid500]

I would build an engine with some torque so you don't need to shift all the time. I was riding my 219 this past weekend for the first time on the trails and it's awesome. I was in 4th and 5th gear most of the day. Once and a while I would hit 3rd on and up hill with a corner. It's nice to have some serious pull of the stroker crank, less shifting and you can keep the rpm's down saving gas and engine life.

[Shorty]

Geenhuman what do you mean by ''Nasty 200x motors''? Have you ever built one of those 68x70mm Stroker big bore 200x motors? Or just ones with a powroll 218 kit? Also how large of a stroke can you do on a 200x without useing a spacer plate? I think its when you hit 67mm when you have to use a 5mm spacer plate.

[greenhuman]

66mm LR x 70 bore, 32mm inlet, 29mm FCR smooth bore on methonal, Spark full race cam, Bassani exhaust etc.
Also 65 stroke x 63 bore with the same add ons. Not only built them, raced them and won many State and National 205cc flat track titles back in the day. Also ran this combo in the 250 class and finished 2nd and 3rd against the watercoolers.
I can also say that just a 218cc in a 70 standard frame will make most riders their pants.

[Shorty]

Do you still have one of these motors? Or maybe a 66mm crank? And what clutch mods did you do?